Online study recruitment is increasingly popular, but we know little about the decision making that goes into joining studies in this manner. In GeneScreen, a genomic screening study that utilized online education and consent, we investigated participants' perceived ease when deciding to join and their understanding of key study features. Individuals were recruited via mailings that directed them to a website where they could learn more about GeneScreen, consent to participate, and complete a survey. Participants found it easy to decide to join GeneScreen and had a good understanding of study features. Multiple regression analyses revealed that ease of deciding to join was related to confidence in one's genetic self-efficacy, limited concerns about genetic screening, trust in and lack of frustration using the website, and the ability to spend a limited time on the website. Understanding of study features was related to using the Internet more frequently and attaining more information about GeneScreen conditions. The ease of deciding to join a genomic screening study and comprehension of its key features should be treated as different phenomena in research and practice. There is a need for a more nuanced understanding of how individuals respond to web-based consent information. © 2017 S. Karger AG, Basel.